Pi Day is a holiday commemorating the mathematical constant π (pi). Pi Day is celebrated on March 14 (or 3/14 in month/day date format), since 3, 1 and 4 are the three most significant digits of π in the decimal form.-Wikepedia
You might ask how an artist who marries a physicist interprets this day. Well,
she tells her husband, "You can have your pi and eat it too!"